The water-water cycle is a major electron sink in Camellia species when CO2 assimilation is restricted.

The water-water cycle (WWC) is thought to dissipate excess excitation energy and balance the ATP/NADPH energy budget under some conditions. However, the importance of the WWC in photosynthetic regulation remains controversy. We observed that three Camellia cultivars exhibited high rates of photosynthetic electron flow under high light when photosynthesis was restricted. We thus tested the hypothesis that the WWC is a major electron sink in the three Camellia cultivars when CO2 assimilation is restricted. Light response curves indicated that the WWC was strongly increased with photorespiration and was positively correlated with extra ATP supplied from other flexible mechanisms excluding linear electron flow, implying that the WWC is an important alternative electron sink to balance ATP/NADPH energy demand for sustaining photorespiration in Camellia cultivars. Interestingly, when photosynthesis was depressed by the decreases in stomatal and mesophyll conductance, the rates of photosynthetic electron flow through photosystem II declined slightly and the rates of WWC was enhanced. Furthermore, the increased electron flow of WWC was positively correlated with the ratio of Rubisco oxygenation to carboxylation, supporting the involvement of alternative electron flow in balancing the ATP/NADPH energy budget. We propose that the WWC is a crucial electron sink to regulate ATP/NADPH energy budget and dissipate excess energy excitation in Camellia species when CO2 assimilation is restricted.

Antihyperalgesic effect of 5-HT7 receptor activation on the midbrain periaqueductal gray in a rat model of neuropathic pain.

The 5-HT7 receptor is the most recently discovered receptor for 5-hydroxytryptamine (5-HT), and only little is known about the analgesic potential of this receptor. Adenosine triphosphate (ATP) modulates pain transmission by activating P2X/P2Y receptors, in which the P2X3 subtype is an important target for this effect. This study examined the antihyperalgesic effect of the 5-HT7 receptors in the ventrolateral midbrain periaqueductal gray (vlPAG), a crucial site for endogenous pain inhibition. This study also explored the importance of the interactions between the 5-HT7 and P2X3 receptors in this effect. To address this issue, neuropathic pain was induced through chronic constriction injury (CCI) of the sciatic nerve in Sprague-Dawley (SD) rats. The expression level and distribution of the 5-HT7 receptor were evaluated through Western blot and immunohistochemistry. The mechanical withdrawal threshold (MWT) was measured by using an electronic pressure meter test. Different doses (3, 6, and 12µmol) of AS-19, a selective agonist of the 5-HT7 receptor, were administered in the vlPAG of CCI rats. The effects of pretreatment with the selective 5-HT7 receptor antagonist SB-269970 or the selective P2X3 receptor antagonist A-317491 on the analgesic effect of AS-19 were observed. Results showed that CCI decreased the MWT values of the rats. The injury also increased the protein level of the 5-HT7 receptor in the vlPAG of neuropathic pain rats. AS-19 microinjection significantly elevated the MWT values in a dose-dependent manner, but SB-269970 pretreatment attenuated the antihyperalgesic effect of AS-19. Furthermore, the antihyperalgesic effect of the 5-HT7 receptor was partially but significantly blocked by A-317491 pretreatment. These data indicate that the 5-HT7 receptor in the vlPAG exerts an antihyperalgesic effect on rats with neuropathic pain. The 5-HT7 and P2X3 receptors interact in the vlPAG and exhibit an analgesic action through the enhanced function of the endogenous analgesic system.

How do leaf anatomies and photosynthesis of three Rhododendron species relate to their natural environments?

BACKGROUND: Rhododendron is one of the most well-known alpine flowers. In order to identify performances relating to Rhododendron's natural habitats we investigated the leaf anatomical structures and photosynthetic characteristics of R. yunnanense, R. irroratum and R. delavayi, which showed different responses after being transplanted into a common environment. RESULTS: When compared with R. irroratum and R. delavayi, R. yunnanense had lower leaf dry mass per unit area (LMA) and larger stomata, but smaller stomatal density (SD) and total stomata apparatus area percent (At), lower stomatal conductance (Gs), transpiration rate (Tr), light compensation point (LCP), light saturation point (LSP), light-saturated photosynthetic rate (Amax) and leaf nitrogen content per unit area (Na). LMA was positively correlated with Amax and maximum rates of carboxylation (Vcmax). However, leaf N content was not significantly correlated with Amax. Thus, the variation in leaf photosynthesis among species was regulated largely by changes in LMA, rather than the concent of nitrogen in leaf tissue. CONCLUSIONS: R. yunnanense plants are vulnerable to moisture and light stress, while R. irroratum and R. delavayi are better suited to dry and high radiation environments. The present results contribute to our understanding physiological trait divergence in Rhododendron, as well benefit introduction and domestication efforts for the three species of Rhododendron studied in this work.

[Effect of tangzu yuyang ointment on the outcome event of patients with chronic diabetic foot ulcers].

OBJECTIVE: To assess the efficacy and safety of Tangzu Yuyang Ointment (TYO) for treatment of chronic diabetic foot ulcers. METHODS: Fifty-seven patients with chronic diabetic foot ulcers of Wagner's ulcer grade 1 to 3 were randomly assigned to the control group (29 cases) and the treatment group (28 cases). Patients in the control group received the standard wound therapy (SWT), while those in the treatment group received SWT plus TYO. The ulcer healing rate, the ulcer improvement rate and the incidence of adverse events were compared between the two groups. Totally 48 patients finished the final follow-ups and entered the data analysis. RESULTS: The ulcer improvement rate was 79.2% in the TYO group and 41.7% in the SWT group (P=0.017) at the 12th week, and 91.7% vs. 62.5% (P=0.036) at the 24th week. There was no statistical difference in the ulcer healing rate and the incidence of adverse events between the two groups at week 4, 12, and 24, respectively. The ulcer healing time was 96 +/- 56 days in the TYO group and 75 +/- 53 days in the SWT group, showing insignificant difference (P=0.271). CONCLUSION: TYO plus SWT was more safe and effective than SWT alone in the treatment of chronic diabetic foot ulcers.

Reversible immortalization of rat pancreatic ß cells with a novel immortalizing and tamoxifen-mediated self-recombination tricistronic vector.

Although the strategy of "Cre/LoxP-based reversible immortalization" holds great promise to overcome the cellular senescence of primary cell cultures for their further use, a secondary gene transfer for Cre expression is usually utilized to trigger the excision of the immortalizing genes in a large number of cells, thus presenting a formidable hurdle for large-scale application. We modified the strategy by utilizing a tricistronic retroviral vector pLCRSTP, in which Cre-ER, simian virus 40 large T antigen (SV40LTAg) oncogene, and a reporter gene were flanked by the same pair of LoxA sites. Five immortalized rat pancreatic ß cell clones transduced with pLCRSTP, and six immortalized rat pancreatic ß cell clones co-transduced with pLCRSTP and another vector encoding the human telomerase reverse transcriptase (hTERT) gene, were obtained, respectively. The Cre-ER protein could be induced to translocate from the cytoplasm to the nucleus by 4-hydroxytamoxifen to make SV40LTAg, hTERT and the Cre-ER gene itself excise without a secondary gene transfer. Our studies suggest that this system is useful to expand rat ß cells and may allow for large-scale production due to its simpler manipulation.

[Development of new SSR markers from EST of SSH cDNA libraries on rose fragrance].

The new SSR markers of rose related fragrance were developed based on the SSH cDNA libraries of rose floral scent mutant. In this study, 10 EST-SSRs (2.6%) from 391 ESTs in the libraries were identified. Six EST-SSRs primers were designed to sequence flanking SSRs. The primer pairs designed were screened on the wild-type Jinyindao, which has flowers full of pleasant scent, and the mutant-type Wangriqinghuai without perceivable floral scent. Five primer pairs were amplified effectively in Jinyindao and Wangriqinghuai, and 3 were polymorphic between Jinyindao and Wangriqinghuai. Eighteen rose cultivars including fragrant roses and nonfragrant roses were identified by the five prime pairs. These results proved that EST-SSR markers are effective markers to identify the polymorphism of the rose.

A study of preoperative methionine-depleting parenteral nutrition plus chemotherapy in gastric cancer patients.

AIM:To investigate the interference of methionine-free parenteral nutrition plus 5-Fu (-MetTPN+5-Fu) in gastric cancer cell kinetics and the side effects of the regimen.METHODS:Fifteen patients with advanced gastric cancer were randomly divided intotwo groups, 7 patients were given preoperatively a seven-day course of standard parenteral nutrition in combination with a five-day course of chemotherapy (sTPN+5-Fu), while the other 8 patients were given methionine-deprived parenteral nutrition and 5-Fu (-MetTPN+5-Fu). Cell cycles of gastric cancer and normal mucosa were studied by flow cytometry (FCM). Blood samples were taken to measure the serum protein, methionine (Met) and cysteine (Cys) levels, and liver and kidney functions.RESULTS:As compared with the results obtained before the treatment, the percentage of G(0)/G(1) tumor cells increased and that of S phase decreased in the -MetTPN+5-Fu group, while the contrary was observed in the sTPN+5-Fu group. Except that the ALT, AST and AKP levels were slightly increased in a few cases receiving -MetTPN+5-Fu, all the other biochemical parameters were within normal limits. Serum Cys level decreased slightly after the treatment in both groups. Serum Met level of patients receiving sTPN+5-Fu was somewhat higher after treatment than that before treatment; however, no significant change occurred in the -MetTPN+5-Fu group, nor operative complications in both groups.CONCLUSION:-MetTPN+5-Fu exerted a suppressive effect on cancer cell proliferation, probably through a double mechanism of creating a state of "Met starvation" adverse to the tumor cell cycle, and by allowing 5-Fu to kill specifically cells in S phase. Preoperative shortterm administration of -MetTPN+5-Fu had little undesirable effect on host metabolism.